Rising temperatures of 1.5–4 °C by the end of the twenty-frst century and continuing after 2100 have caused climate change to threaten food security. Indeed, the rainfed production of strategic crops such as wheat in countries such as Iran, which are likely to be highly afected by climate change, is very important. This study aimed to identify the suitable areas for rainfed wheat cultivation and the yield gap estimation in current and future climatic conditions using geographical analysis, a crop simulation model, and the GYGA protocol in Iran. For this, environmental variables (including average, minimum, and maximum temperatures, rainfall) along with topographic (slope, elevation) and edaphic components (such as organic carbon, pH, EC, [CaCO3], exchangeable sodium percentage, cation exchange capacity, and soil erosion) were involved. The results revealed that around 30% of the total areas (6.62 million ha) are not suitable at all, while just 13% of total lands (2.97 million ha) were highly suitable and suitable. These areas are mainly located in the northern part of Iran. The study of the climate change scenarios indicated that the northern, northwestern, and western parts of the country have great potential for rainfed wheat production and future climate change will beneft wheat production in these areas, but in other parts of the country, more unfavorable conditions are expected. The mean water-limited potential yield (Yw) diference between marginally suitable to not suitable classes was narrow (<0.3 t ha−1), while for highly suitable to moderately suitable classes was about 2.5 t ha−1.

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